This alternative will have no planned construction; US 101 will continue on its existing alignment. Regular maintenance and operations will continue, with emergency restoration projects as needed. Current annual maintenance costs of $2 million with a projected cost of approximately $26 million by 2034. Engineering solutions such as retaining walls have not been able to provide long-term stability, but will continue to be necessary to provide an adequate highway facility. As the landslide moves slowly, the road will require costly repairs and maintenance with potential environmental impacts including old-growth redwood impacts associated with minor retreats to keep the roadway open. A future slide might occur that is deep and large enough that it could result in a major failure of the roadway and complete closure of the roadway indefinitely. A major failure would have economic impacts and require a significant detour that is outlined in 9.2.3 Economic Impact Study. Some potential options closest to the existing alignment include a retreat upslope that could require taking more than 100 old-growth trees. For a more detailed explanation, please refer to page 15 of the Engineered Feasibility Study, available in the Document Library.

On the map, the red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

(Includes 2,000 foot tunnel)

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.0 min

New Construction

Length: 3.4 mi

Footprint: 77 acres

Schedule: 3 years

Cost (in Millions)

Minimum: $520M

Maximum: $710M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 54 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 1 acre

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

Please note the following:

• Lines on the map indicate the width of each corridor, not the exact placement of the roadway.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal and mitigation.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 0.8 min

New Construction

Length: 3.5 mi

Footprint: 80 acres

Schedule: 2 years

Cost (in Millions)

Minimum: $320M

Maximum: $380M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 56 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 3 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

Please note the following:

• Lines on the map indicate the width of each corridor, not the exact placement of the roadway.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal and mitigation.

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

(Includes 2,000 foot tunnel)

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 0.4 min

New Construction

Length: 3.7 mi

Footprint: 89 acres

Schedule: 3 years

Cost (in Millions)

Minimum: $550M

Maximum: $730M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 65 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 1 acre

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 0.2 min

New Construction

Length: 3.7 mi

Footprint: 92 acres

Schedule: 2 years

Cost (in Millions)

Minimum: $340M

Maximum: $400M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 67 acres

Mature Redwood Forest: 0 acres

Old Growth Redwood Forest: 3 acres

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.7 min

New Construction

Length: 8.2 mi

Footprint: 250 acres

Schedule: 3 years

Cost (in Millions)

Minimum: $750M

Maximum: $870M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 205 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

Please note the following:

• Lines on the map indicate the width of each corridor, not the exact placement of the roadway.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal and mitigation.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.5 min

New Construction

Length: 9.0 mi

Footprint: 270 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $820M

Maximum: $950M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 205 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

Please note the following:

• Lines on the map indicate the width of each corridor, not the exact placement of the roadway.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal and mitigation.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 2.6 min

New Construction

Length: 12.2 mi

Footprint: 332 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,200M

Maximum: $1,300M

Existing Habitat Type

Coastal scrub/grassland /spruce: 7 acres

Riparian: 1 acre

Clear cut: 13 acres

Young Redwood Forest: 217 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

Please note the following:

• Lines on the map indicate the width of each corridor, not the exact placement of the roadway.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal and mitigation.

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.2 min

New Construction

Length: 8.4 mi

Footprint: 262 acres

Schedule: 3 years

Cost (in Millions)

Minimum: $770M

Maximum: $900M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 216 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.0 min

New Construction

Length: 9.3 mi

Footprint: 282 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $840M

Maximum: $980M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 216 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 2.0 min

New Construction

Length: 12.5 mi

Footprint: 344 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,130M

Maximum: $1,320M

Existing Habitat Type

Coastal scrub/grassland /spruce: 12 acres

Riparian: 1 acre

Clear cut: 10 acres

Young Redwood Forest: 228 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 4.1 min

New Construction

Length: 11.4 mi

Footprint: 299 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,020M

Maximum: $1,200M

Existing Habitat Type

Coastal scrub/grassland /spruce: 0 acres

Riparian: 22 acres

Clear cut: 0 acres

Young Redwood Forest: 254 acres

Mature Redwood Forest: 23 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 3.9 min

New Construction

Length: 12.2 mi

Footprint: 319 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,100M

Maximum: $1,280M

Existing Habitat Type

Coastal scrub/grassland /spruce: 0 acres

Riparian: 22 acres

Clear cut: 0 acres

Young Redwood Forest: 254 acres

Mature Redwood Forest: 43 acres

Old Growth Redwood Forest: 0 acres

BASIS FOR ALTERNATIVE EXCLUSION

The criteria used for alternative exclusion includes geotechnical, environmental, engineering, and planning as a baseline used to evaluate alternatives. For this Feasibility Study, the primary impacts to avoid are natural resources and cultural landscape. An essential question answered in this process is whether an alternative provides a unique advantage over other alternatives being proposed. For a more detailed explanation, please refer to page 28 of the Engineered Feasibility Study, available in the Document Library.

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 5.0 min

New Construction

Length: 15.5 mi

Footprint: 381 acres

Schedule: 4 years

Cost (in Millions)

Minimum: $1,390M

Maximum: $1,620M

Existing Habitat Type

Coastal scrub/grassland /spruce: 0 acres

Riparian: 22 acres

Clear cut: 2 acres

Young Redwood Forest: 264 acres

Mature Redwood Forest: 93 acres

Old Growth Redwood Forest: 0 acres

(5,400 foot tunnel)

Travel Time
(Wilson Creek Rd. to Hamilton Rd.)

Added Time: 1.0 min

New Construction

Length: 1.3 mi

Footprint: 4 acres

Schedule: 6.5 years

Cost (in Millions)

Minimum: $690M

Maximum: $1,060M

Existing Habitat Type

Coastal scrub/grassland /spruce: 2 acres

Riparian: 0 acres

Clear cut: 0 acres

Young Redwood Forest: 0 acres

Mature Redwood Forest: 1 acre

Old Growth Redwood Forest: 1 acre

On the map, the alternative is denoted with a letter and a number, if the alternative has multiple segment options. The red line indicates the current Last Chance Grade alignment and the pink area indicates the landslide area.

Please note the following:

• Lines on the map indicate the width of each corridor, not the exact placement of the roadway.
• The acreages of “Existing Habitat Type” are estimates based on overall analyses of habitat types in the area.
• Costs are estimated and include construction, materials disposal and mitigation.